fix(tools): reject parent-directory segments in Claude memory paths

[aniruddhaadak80]

Summary\nFixes path-traversal bypass in \ClaudeMemoryTool.isValidPath\ (\packages/tools/src/claude-memory.ts). The previous check looked for the substring ../\ only, so /memories/..\ and /memories/foo/..\ passed validation and were treated as valid memory paths. Now any path segment equal to ..\ is rejected (Windows ..\\\ still rejected as before).\n\n## Changes\n- \packages/tools/src/claude-memory.ts: segment-based ..\ rejection in \isValidPath\n- \packages/tools/src/claude-memory.test.ts: regression tests for /memories/.., /memories/foo/.., /memories/../secrets.txt\ asserting \Invalid path\ with no document fetch\n\n## Testing\n- Repro before fix via isolated check: /memories/..\ -> true, /memories/foo/..\ -> true (should be false)\n- \�unx vitest run src/claude-memory.test.ts: 13 passed\n- \�unx vitest run src/tools-shared.test.ts src/claude-memory.test.ts: 26 passed\n- \�unx biome check src/claude-memory.ts src/claude-memory.test.ts: clean\n- Pre-existing, unrelated: \�unx tsc --noEmit\ fails on \ sconfig baseUrl\ (upstream #1545 class), \src/tool-operations.test.ts\ fails on @ai-sdk/provider-utils lazyValidator\ export mismatch — both reproduce without this change\n\n## Notes\n- No behavior change for valid paths (/memories, /memories/, /memories/notes.txt\ still accepted)\n- AI assistance used for drafting; all code run and verified locally by contributor